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Boy, You Got My
Heartbeat Runnin' Away
An electrocardiogram (ECG aka EKG) reflects the electrical
activity of the cardiac cells of the heart.
Detects cardiac dysrhythmias, location and extent of
myocardial infarction, cardiac hypertrophy, and can also
evaluate the effectiveness of cardiac medications.
P wave: atrial depolarization
PR segment: delay of conduction through the AV node
PR interval: impulse travel time through the AV node
(0.12 - 0.20 s)
QRS complex: ventricular depolarization (0.04 - 0.10 s)
ST-segment: the beginning of ventricular repolarization
T wave: ventricular repolarization and ventricular diastole
U wave: follows T wave; may indicate an electrolyte
abnormality
Isoelectric line: flat baseline
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Can't You Hear That
'Lub Dub' Bass?
Electrical Conduction Pathway
Normal rate:
60 - 100 bpm
Normal rate:
40 - 60 bpm
Normal rate:
40 - 60 bpm
Normal rate:
20 - 40 bpm
SAVe HIS KIN
SA Node -> AV Node --> Bundle of HIS --> PurKINje Fibers
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12-lead EKG Placement
v1 = 4th intercostal space; right sternum
v2 = 4th intercostal space; left sternum
v3 = Between v2 and v4
v4 = 5th intercostal space; mid-clavicular line
v5 = Anterior axillary line (level with v4)
v6 = Mid-axillary line (level with v4 & v5)
RA = Right forearm/wrist
LA = Left forearm/wrist
RL = Right lower leg/proximal ankle
LL = Left lower leg/proximal ankle
BarbiEKG
Tingz
7 Steps to Analyzing EKGs
Rate
Are the atrial and ventricular rates the same?
Bradycardia
Tachycardia
<60 bpm
>60 bpm
Rhythm
Note the distance between P waves and R waves
Regular = no consistent variations
Irregular = 1+ consistent variations
P wave
Is there a P wave before every QRS complex?
Yes = rhythm began in the SA node
No
Do all P waves have the same size and shape?
Yes = impulse began in the SA node
No
PR Interval
QRS Complex
ST Segment
T Wave
Are the PR intervals within normal range (0.12 - 0.20 sec)?
Yes = no interference in conduction from SA to AV node
No
Are the QRS complexes within normal range (0.04 - 0.10 sec)?
Yes = no interference in conduction
No = if > 0.12 sec, delay occurred in ventricles
Examine the ST segment:
Isoelectric? [flat]
Depressed? [dip]
Elevated? [bump]
Are the T waves rounded and the same size/shape?
Yes = rounded shape
No = inverted shape
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